<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>Document</title>
</head>
<body>
	<form action="">

			<!-- autofocus 自动获取焦点 -->
			<!-- autocomplete  自动完成 -->
			<!-- required  必须要填写 -->
			<!-- readonly	只读。 -->
			<!-- novalidate  表示不校验 -->



  <input type="text"    placeholder="输入搜索关键字" readonly required  autocomplete  autofocus novalidate>

	</form>
</body>
</html>